Valopicitabine combined with pegylated interferon demonstrated significantly greater viral suppression after 12 weeks of treatment compared to retreatment with ribavirin plus pegylated interferon in chronic Hepatitis C, genotype 1 patients who were non- responders to previous therapy. Valopicitabine, a novel polymerase inhibitor, is being developed by Idenix Pharmaceuticals Inc. a biopharmaceutical company engaged in the discovery and development of drugs for the treatment of human viral and other infectious diseases.
Dr. Christopher O'Brien, professor of clinical medicine at the University of Miami and a principal investigator in an ongoing Phase IIb clinical trial of valopicitabine, presented 12-week data from this Phase IIb clinical trial on, November 14, 2005 at the 56th Annual Meeting of the American Association for the Study of Liver Diseases (AASLD) held in San Francisco.
"At 12 weeks, the combination of valopicitabine plus Pegasys produced a statistically significant improvement in suppression of Hepatitis C virus (HCV) replication and a significantly higher proportion of patients achieving an early virologic response (EVR) compared to patients retreated with Pegasys and ribavirin," said Dr. O'Brien. "These are promising results, particularly for the many treatment-refractory patients in urgent need of new therapeutic options."
The Phase IIb clinical trial in treatment-refractory patients is designed to evaluate different dosing regimens of valopicitabine in combination with pegylated interferon and to compare this combination with the combination therapy of pegylated interferon plus ribavirin. At 12 weeks of treatment, the two higher-dose arms of valopicitabine plus Pegasys showed significantly greater suppression of serum HCV RNA compared to the ribavirin plus Pegasys retreatment arm, states a company release.
"These encouraging data support continued evaluation of combination treatment with valopicitabine and pegylated interferon in both treatment- refractory and treatment-naive Hepatitis C patients. We look forward to initiating our Phase III programme for valopicitabine in treatment-refractory patients in early 2006," said Nathaniel Brown, executive vice president of clinical development and chief medical officer of Idenix
In the Phase IIb clinical trial, valopicitabine has demonstrated satisfactory safety and tolerance overall. A low percentage of patients on valopicitabine have discontinued due to adverse events. Two serious adverse events were considered attributable to combination treatment with valopicitabine plus pegylated interferon (anaemia and dehydration) and both resolved. To date, there has been no predominant treatment-limiting adverse event or laboratory abnormality observed for combination treatment with valopicitabine and pegylated interferon.
At the end of November, Idenix anticipates reviewing with the FDA the available data from the valopicitabine clinical development programme, including data from this Phase IIb clinical trial during an end-of-Phase II meeting.
Valopicitabine, which is administered orally once a day, is intended to block HCV replication by specifically inhibiting the HCV RNA polymerase, the enzyme that makes new copies of the HCV viral chromosome inside infected cells.
Hepatitis C is an infectious liver disease caused by the hepatitis C virus. The World Health Organisation estimates that 170 million individuals worldwide carry chronic HCV infection, with 3 to 4 million new infections occurring globally each year. It is the most common chronic blood-borne infection in the United States.